Door assembly

ABSTRACT

A door assembly for a garage or the like. The door assembly including a pair of horizontally disposed panels hingedly connected to one another about a horizontal axis and spring activated tensioning means for opening and closing the door assembly to provide a power assist in both the opening and closing actions. The door assembly being particularly suitable for mounting in a frame in a factory production line as the locking hardware and power assist hardware may be operably mounted in a frame so that the installation required is limited to the location of the frame in a door opening. The door assembly is also particularly suitable for double garage door structure as two independent doors may be mounted in one frame.

[ 51 Apr. 25, 1972 1 DOOR ASSEMBLY [72] Inventor: Allan M. Buehler, l-lespeler, Ontario,

Canada [73] Assignee: Trlgroup Industries Ltd., Hamilton, On-

tario, Canada 22 Filed: May 12,1970

21 Appl.No.: 36,571

[52] U.S. Cl ..l60/207 Smith Hasselmark 160/207 Primary Examiner-.1. Karl Bell Attarney--Fetherstonhaugh & Co.

[5 7] ABSTRACT A door assembly for a garage or the like. The door assembly including a pair of horizontally disposed panels hingedly connected to one another about a horizontal axis and spring activated tensioning means for opening and closing the door assembly to provide a power assist in both the opening and closing actions. The door assembly being particularly suitable for mounting in a frame in a factory production line as the locking hardware and power assist hardware may be operably mounted in a frame so that the installation required is limited to the location of the frame in a door opening. The door assembly is also particularly suitable for double garage door structure as two independent doors may be mounted in one frame.

12 Claims, 8 Drawing Figu-es PATENTEDAPRZB I972 3,658,114

SHEET 10F 3 FIGZ 26 FIGB 52 2 INVENTOR. ALAN M. BUEH LER ATTORNEYS PATENTEDAPR 2 5 I972 SHEET 2 BF 3 INVENTOR.

ALAN M. BUEHLER BY flfigh FIG. 8

ATTORNEYS PATENTEDAPR 25 I972 SHEET 3 BF 3 RN EYS INVENTOR ALAN M. BUEHLER ATTO DOOR ASSEMBLY FIELD OF INVENTION This invention relates to door assemblies. In particular, the invention relates to a door assembly of the type suitable for a garage.

PRIOR ART Garage doors are generally relatively large structures which are normally manually opened and closed with the aid of tensioning springs. The assistance which the conventional tensioning spring gives in the opening of a door is somewhat limited to the early stages of the opening of the door. The springs which are used in the conventional one piece door are normally tension springs which are not capable of providing any substantial amount of assistance over a major portion of the movement of the door during opening and closing. In addition, the springs do not provide a power assist in the closing of the door. Furthermore, known springs generally extend between a connection to the door and a connection to the door jamb and, as a result of this construction, the springs are usually installed when the door is being fitted into the garage opening. The conventional door is a single panel which requires an overhead guide rail to be fitted within the garage to maintain the door in the open elevated position.

The conventional garage door assembly is locked by means of a latch which communicates between the door assembly and the support frame or the ground underlying the lower edge of the door. As a result of this method of mounting the lock, it is not possible to provide the pre-assembled door unit with a fully operational lock assembly. When a door is to be installed, it is necessary either to form a lock opening in the frame or at least to mount the lock in a position to cooperate with the frame or an opening formed in the ground underlying the lower edge of the door.

A further difficulty experienced in garage door assemblies is in the double-car garage structure. The larger door openings of this type of garage require either two separate doors or one large door. If a very large door is used, it is very difficult to open and close manually. If two conventional doors are used, a central brick or concrete pillar is essential to ensure that the doors may be properly aligned. The central pillar is, however, undesirable as it reduces the effective width of the door opening and it forms an obstruction in the garage door opening which is easily struck when maneuvering a motor vehicle in and out of the garage.

The present invention overcomes the difficulties of prior art described above by providing a door assembly which is adapted to provide a powerassist in both opening and closing of the door.

SUMMARY A further feature of the present invention is the provision of a door assembly which may be locked in a closed position by lock means carried by the door without requiring a complementary element carried by the door frame.

The present invention also provides a pre-assembled door and frame structure which includes a spring actuated opening and closing device and wherein the tension applied by the spring may be preset in a factory production assembly operation.

According to an embodiment of the present invention, a garage door assembly comprises an upper door panel adapted to be pivotally mounted at its upper end for pivoting about the first generally horizontal axis and a lower door panel pivotally mounted to the upper door panel to pivot about a second horizontal axis. The assembly also includes tensioning means for connecting the upper and lower panels in a substantially vertical tensioning plane. The panels are movable from the closed position wherein they are vertically aligned with one another to form a closed door. In this position, the second horizontal axis is disposed on one side of said tension plane and the doors are movable from the first position toa second position wherein they are elevated and folded one upon the other in a face-to-face relationship with the second axis disposed on the other side of said tensioning plane. The tensioning means applies a closing moment to the panels when the second axis is on one side of the tensioning plane and an opening moment when the second axis is on the other side of the tensioning plane.

According to a further embodiment of this invention, there is provided a garage door assembly as described above, including a frame in which the door is hung in order to provide a selfcontained operational door.

PREFERRED EMBODIMENTS The invention will be more clearly understood after reference to the following detailed specification read in conjunction with the drawings, wherein,

FIG. 1 is a pictorial view of the inner side of a garage door assembly according to an embodiment of the present inventron;

FIG. 2 is an enlarged detailed view taken along the line 2-2 of FIG. 1;

FIG. 3 is an enlarged detailed view taken along the line 33 of FIG. 1;

FIG. 4 is a fragmentary view showing the locking means for locking the upper and lower panels in a closed position relative to one another;

FIG. 5 is an enlarged detailed view ofa portion of the door illustrated in FIG. 1;

FIG. 6 is a pictorial view similar to FIG. 1 showing a double door structure;

FIG. 7 is an enlarged detailed view taken along the line 77 of FIG. 6 when both doors are closed; and

FIG. 8 is a detailed view taken along the line 8-8 of FIG. 6.

In FIG. 1 of the drawings, reference numeral 10 refers to a door assembly according to an embodiment of the present invention. The assembly illustrated in FIG. 1 consists of an upper door panel 12 and a lower door panel 14. The assembly also includes a frame which consists of a pair of uprights l6 and a transverse cross-bar member 18 connecting the upper ends of the upper edge 16. The door 12 is hingedly connected to the horizontal member 18 by hinges 20. The upper and lower panels are hingedly connected to one another by means of a hinge 22 (see FIG. 4) which is connected to the outer surfaces ofthe panels 12 and 14 to permit the door to hinge about the second horizontal axis, which is disposed parallel to the horizontal axis of the hinges 20. A guide track 24 is secured to each of the vertical members 16 and a guide runner assembly generally identified by the numeral 26 is secured to the inner face of the lower door and extends into the guide track to be guided therein, as will be described hereinafter. Door lock assemblies 28 are mounted adjacent the second hinge line to lock the upper panel relative to the lower panel. The locking devices 28 are adapted to be released by a manually engageable handle mounted on the outer face of the door and the movement of the handle is transmitted to the locking devices 28 by a lever arm 30 and connecting rods 32. This type of hand operated control is well known in garage doors which are presently in use. A pair of brackets 34 are mounted on the inner side of the upper panel 12 to project inwardly and to rotatably receive a shaft 36 therein. A coil spring 38 extends around the shaft 36 and is secured at one end to one of the brackets 34 and at the other end it is secured to the shaft 36. A pulley 40 is mounted on each end of the shaft for rotation therewith and a tensioning cable 42 extends downwardly from the pulley 40 and is connected at its lower end to the assembly 26. The details of the construction shown in FIG. 1 will be more clearly understood with reference to FIGS. 2 to 5 inclusive.

In FIG. 2 of the drawings, it will be seen that the transversely extending support member 18 is Z-shaped in section and may be secured to a jamb 44 by conventional screws 46. The

hinge 20 is also shown in FIG. 2 and it will be noted that the panel 12 is seen to pivot through at least 90 from the position shown therein. The outward movement of the panel 12 is, however, restricted by the downwardly projecting portion of the bracket 18 such that when the garage door is mounted in the operative position, the upper panel 12 is only permitted to pivot rearwardly. This feature contributes to the fact that the door assembly of the present invention may be locked by providing a lock which prevents pivoting about the axis connecting the upper and lower door panels.

In FIG. 3 of the drawings, the guide track assembly is illustrated. It will be seen that the vertical support pillars 16 are generally L-shaped and have a portion 16a which, in use, is connected to a jamb 48 by conventional screws 50. The guide track 24 is in the form of a channel having inwardly projecting outer edges. The runner assembly 26 includes a bracket 52 mounted on the inner face of the lower panel 14 by conventional screws. A shaft 54 extends transversely from the bracket 52 and a roller 56 is mounted at the outer end of the shaft 54. The roller 56 is proportioned to ride within the track and to reciprocate therein when the door moves from the open and closed positions. It will be noted that the roller 56 is within the track 24 in all possible positions of the door such that while the lower panel 14 is free to pivot about the axis of the shafts 54, it is not possible to open the door other than by elevating the lower panel 14.

In FIG. 4 of the drawings, the locking mechanism for locking the two doors together is illustrated. The lock consists of an upper catch 58 and a lower latch 60. The latch 60 has a roller 62 mounted therein and the upper catch 58 has a shoulder 64 formed therein. When the two halves of the door are moved to the closed position, the roller 62 rolls over the catch 58 and engages the shoulder 64. To release the lock, the lever 60 is turned and the connecting rods 32 pull the latch 60 away from the catch 58 to move the roller 62 inwardly over the shoulder 64.

FIG. of the drawings shows the assembled structure of the door in more detail. In FIG. 5, it will be seen that the pulley 40 is conically shaped and has a helical groove formed therein to receive the tension applying cable 42. It will also be seen that the spring 38 is secured at its outer end to the bracket 34 and at its inner end it is secured to the shaft 36 by means of a clamping screw 39.

The torque which is applied to the pulley 40 by the spring 38 is at its greatest when the door is in the closed position and, consequently, they cable is applied to the enlarged portion of the pulley 40. As the spring unwinds, the torque applied to the shaft will be decreased. However, the decreasing diameter of the pulley will serve to supply substantially constant tension to the cable 42 so that the door will operate very smoothly. The spring 38 is set so as to continuously apply a torque to the pulley 40 to pull the cable 42 onto the pulley. The spring is adjusted so that the pulley will be driven a sufficient extent to ensure that assistance in the opening of the door is provided even when the cable 42 is almost all wound onto the drum 40. The tension latch members 58 and 60 are again shown in FIG. 5 in the drawings in more detail.

A double garage door structure is illustrated in FIG. 6 of the drawings. Again, the structure includes vertical frame members l6 and the horizontal frame member 18. It will be noted that there is no central pillar dividing the two doors. The doors consist of upper panels 12a and 12b and lower panels 14a and 14b. The structure of the door and the operating mechanism is substantially the same to that previously described with reference to FIGS. 1 to 5 and like numerals refer to like parts throughout FIGS. 1 to 6. The main differences are that each door only has one guide track 24. The two doors operate independently of one another and are locked in the closed position by the locking mechanism 28, previously described, and by means of a ground lock structure generally identified by the reference numeral 66, illustrated in detail in FIG. 8. The ground lock is connected to the hand operated release mechanism 30 by means of a further connecting rod 32. In

FIG. 8 of the drawings, the detailed structure of the closure device 66 is illustrated. The closure device 66 consists of a bracket 68, which is secured to the door panel 14a, and a bracket which is grouted into the garage floor by a conventional grouting bolt 72. A blade 74 is slidably mounted in the bracket 68 and it isurged downwardly by means of a coil spring 76. To release the catch, the connecting rod 32 is pulled by the hand operated lever 30 and this raises the slide 74 above the upper edges of the bracket 70 so that the door may be pivoted into an open position.

FIG. 7 of the drawings illustrates a suitable seal for sealing one door against the other. The doors 14a and 14b each have a flexible sealing lip 80 secured thereto and extending longitudinally thereof. The sealing lips 80 are adapted to abut one another when the doors are in a closed position to seal the one door against the other. A similar seal is provided between the panels 12a and 12b. The lower end of the tension cables 42 which are mounted on the inner release of the double door structure are secured to the brackets 82 which are shown in FIGS. 6 and 7 of the drawings.

In operation, the door illustrated in the drawings is movable from the closed position shown in one-half of FIG. 6 to the open position shown in the other half of FIG. 6. In the closed position, panels and are aligned with one another and the axis of the pivot connecting the panels 12 and I4 is disposed forwardly of the plane of the tension cable 42 such that the tension in the cable 42 applies a closing moment to panels 120 and 140 about the secondary horizontal axis which joins these two panels.

The door is maintained in the aligned position by the locks 28 and it is retained within the door frame by hinges 20 and the cooperative relationship of the guide rail 24 and the roller 56. In addition, in the double door structure, the ground engaging lock 66 servesto further retain the door in a closed position. In the single door structure, the lock 66 is not essential as a guide wheel is provided at both edges of the door. It is not possible to open the door illustrated in FIG. 1 or in FIG. 6 other than by releasing the locks 28 and 66. To release the locks 28 and 66, the normal cranking handle is turned and the locks are released by the connecting wires 32. When the locks have been released, the lower edge of the door may be pulled outwardly or, alternatively, the center portion of the door may be pushed inwardly so that the lower panel 14 will pivot about the rollers 56. During this initial opening stage, the secondary horizontal axis begins to move rearwardly as the upper panel 120 pivots around the hinges 20. During the initial opening period, it is necessary to overcome the closing moment applied to the door by the tension device. However, after the secondary pivot point moves rearwardly of the plane of the tension cable 42, the tension in the cable 42 assists the opening action. The tension in the cable 42 will continue to assist in the opening of the door as it moves to the open position shown in FIG. 6 wherein the upper and lower panels are folded one upon the other in a face-to-face relationship. It will be noted that the portion of the lower panel 14 which extends below the level of the roller 56 will project outwardly of the door when in the open position while the remainder of the panel 14a and the upper panel 12b will project inwardly as shown in FIG. 6.

From the foregoing, it will be apparent that the present invention provides an improved garage door construction which is easy to open and close as it provides a power assist for both the opening and closing action. The structure of the door is such that it may be pre-assembled with a preset tension in the spring actuator means on a mass production basis in the factory. In FIG. 5 of the drawing, straps 80 which are shown in broken lines are used to hold the assembled door in a position suitable for shipping as a pre-assembled unit so that the installation of the door assembly only calls for the fitting of the frame into a door opening.

Various modifications of the embodiments of the invention which are illustrated in the drawings will be apparent to those skilled in the art without departing from the scope of this invention.

For example, in a double door frame such as that illustrated in FIG. 6, it is possible to employ a single door which extends over the full width of the opening or to connect the adjacent doors such that they open together. The doors may be connected by a rigid strap or by using a single shaft 36 extending between adjacent doors. By connecting two standard single units together to form a single door, it will be possible to take advantage of the low cost of the standard units while providing a door which will open over the full width of the opening in one opening operation.

in a further modification, where the ground engaging lock 66 which is illustrated in FIG. 8 is provided, it is possible to dispense with the guide track 24 and runner S6. The interconnecting locking devices 28 and ground lock 66 will maintain the door in a closed position. This modified construction will require a bracket 80 to be fitted when the door is installed but it will retain the advantages of the novel operating mechanism of the present invention. It is to be noted, however, that the guide rails 24 and runner 56 considerably improve the controlled opening and closing action of the door. These and other modifications will be readily apparent to those skilled in the art.

What I claim as my invention is:

l. A door assembly for a garage or the like comprising:

a. an upper door panel adapted to be pivotably mounted at its upper edge for pivoting about a first generally horizontal axis, said upper panel having an inner face and an outer face,

b. a lower door panel pivotably mounted to said upper panel to pivot about a second horizontal axis, said lower panel having an inner face and an outer face,

c. tensioning means mounted on an inner face of said panels and connecting said upper and lower panels in a substantially vertical tensioning plane,

d. said panels being movable from a closed position wherein said panels are vertically aligned to form a closed door in a plane which is disposed outwardly from and closely adjacent said tensioning plane, and a second open position wherein said doors are folded about said second horizontal axis and elevated to a position in which said outer faces of said panels are disposed in a face-to-face relationship, said second axis being disposed inwardly from said tensioning plane,

e. said tensioning means applying a closing moment to said panel about said second horizontal axis when said second axis is disposed outwardly from said tensioning plane and an opening moment when said second axis is disposed inwardly from said tensioning plane.

. A door assembly for a garage comprising:

. an upper door panel having an inner face, an outer face,

an upper horizontal edge, a lower horizontal edge and a pair of oppositely disposed vertical side edges,

a lower door panel having an inner face, an outer face, an

upper horizontal edge, a lower horizontal edge and a pair of oppositely disposed vertical side edges,

c. first hinge means for mounting said upper panel in a frame to permit pivoting about a first horizontal axis disposed adjacent said upper edge of said upper panel,

d. second hinge means pivotably connecting said upper and lower panels to permit pivoting of said upper and lower panels relative to one another about a second horizontally extending axis disposed adjacent the lower edge of said upper panel and the upper edge of said lower panel,

e. said upper and lower panels being pivotable about said first and second axes between a closed position wherein said panels are vertically aligned with one another to form a closed door and a second open position wherein said panels are folded to an elevated position wherein the panels are disposed one on top of the other in a generally horizontal position with said outer faces in a face-to-face relationship,

said tensioner mounting means located below said first horizontal axis and secured to and extending rearwardly from the inner face of said upper panel,

g. second tensioner mounting means secured to and extending rearwardly from the inner face of said lower panel,

h. tensioning means mounted on said first tensioner mounting means and connected to said second tensioner mounting means and operable in a substantially vertical plane spaced rearwardly from and adjacent the plane of said doors when in said first closed position and connecting said first and second mounting means to apply a closing moment about said second horizontal axis when said second horizontal axis is disposed forwardly of the plane of said tensioning means and an opening moment when said second horizontal axis is disposed rearwardly of said tensioning plane.

. A garage door assembly comprising:

a prefabricated frame having a pair of vertically extending support pillars and a horizontally extending support member connecting the upper ends of said supports to define a door opening,

. guide track means carried by at least one of said vertical members and extending longitudinally thereof,

. an upper door panel having an inner face, an outer face, an upper horizontal edge, a lower horizontal edge, and a pair of oppositely disposed vertical side edges,

. a lower door panel having an inner face, an outer face, an upper horizontal edge, a lower horizontal edge, and a pair of oppositely disposed vertical side edges,

. first hinge means pivotally mounting said upper panel on said horizontally extending frame member to pivot about a first horizontal axis disposed adjacent the upper edge of said upper panel,

f. second hinge means pivotally connecting said upper and lower panels to permit pivoting of said upper and lower panels relative to one another about a second horizontally extending axis disposed adjacent the lower edge of said upper panel to the upper edge of said lower panel,

. guide track runner means secured to said lower panel and projecting into said guide track to reciprocate therein,

. said guide track runner means being disposed a substantial distance from said second horizontal axis to permit said guide track runner means to reciprocate within said guide track pivoting about said second horizontal axis,

. said upper and lower panels being pivotable about said first and second axes between a closed position wherein the panels are vertically aligned with one another to form a closed door and a second open position wherein said panels are folded to an elevated position wherein the panels are disposed one on top of the other in a generally horizontal position with said outer faces in a face-to-face relationship,

j. first tensioner mounting means located below said first horizontal axis and secured to and extending rearwardly from the inner face of said upper panel,

. second tensioner mounting means secured to and extending rearwardly from the inner face ofsaid lower panel,

. tensioning means mounted on said first tensioner mounting means and connected to said second tensioner mounting means and operable in any substantially vertical plane spaced rearwardly from and adjacent the plane of said doors when in said first closed position and connecting said first and second tensioner mounting means to apply a closing moment throughout said second horizontal axis when said second horizontal axis is disposed forwardly of the plane of said tensioning means and an opening moment when said second horizontal axis is disposed rearwardly of said tensioning plane.

4. An assembly as claimed in claim 1, including releasable locking means communicating between said upper door panel and said lower door panel to prevent pivoting about said second horizontal axis and thereby maintain said door in a closed position.

5. A garage door assembly as claimed in claim 1 wherein said tensioning means comprises a pulley mounted for rotation on one of said door panels and a flexible cable connecting between said pulley and the other of said door panels, and

drive means urging said pulley to rotate in a predetermined direction to apply tension to said cable means in all positions of said upper and lower door panel relative to one another.

6. A garage door assembly as claimed in claim 1 wherein said tensioning means comprises a shaft rotatably carried by said upper door panel for rotation about a generally horizontal axis, coil spring means extending around the outer surface of the shaft and connected to it to urge said shaft to rotate in a predetermined direction, a pulley secured to one end of said shaft for rotation therewith, tension cable means connecting said pulley to said lower door panel, said spring means rotating said pulley to wind said tensioning cable onto said pulley when said door moves from said closed position to said open position.

7. A garage door assembly as claimed in claim 6 wherein said pulley is conically shaped and formed with a helical groove receiving the tensioning cable, the tensioning cable being connected to the pulley in the area of the largest diameter.

8. In a garage door assembly having a frame consisting of a pair of vertically extending support pillars and a horizontally extending support member connecting the upper ends of said support pi ars, the improvement of, two door assemblies as claimed in claim I mounted in a side-by-sider elationship.

9. Ag arge tioor assembly as claimed in claim 8 including sealing means for sealing the oppositely disposed side edges of adjacent door panels.

10. A garage door assembly as claimed in claim 8 including ground engaging lock means carried by the lower panels of each door.

11. A garage door assembly as claimed in claim 8, including releasable locking means communicating between said upper door panels and said lower door panels to prevent pivoting about said second horizontal axis and thereby maintain said door in a closed position.

12. A garage door assembly comprising:

a. a prefabricated frame having a pair of vertically extending support pillars and a horizontally extending support member connecting the upper ends of said supports to define a door opening,

b. guide track means carried by each of said vertical members and extending longitudinally thereof,

c. a pair of door assemblies each comprising d. an upper door panel having an inner face, an outer face,

an upper horizontal edge, a lower horizontal edge, and a pair of oppositely disposed vertical side edges,

. a lower door panel having an inner face, an outer face, an

upper horizontal edge, a lower horizontal edge, and a pair of oppositely disposed vertical side edges,

. first hinge means pivotally mounting each of said upper panels onto said horizontally extending frame member to pivot about a first horizontal axis disposed adjacent the upper edge of said upper panel,

second hinge means pivotally connecting each pair of upper and lower panels to permit pivoting of each pair of connected upper and lower panels relative to one another about a second horizontally extending axis disposed adjacent the lower edge of said upper panel to the upper edge of said lower panel,

h. guide track runner means secured to each lower panel and projecting into the guide track of the adjacent venical support to reciprocate therein,

. said guide track runner means being disposed a substantial distance from said second horizontal axis to permit said guide track runner means to reciprocate within each of said guide tracks pivoting about said second horizontal axis,

. each connected pair of upper and lower panels being pivotable about said first and second axes between a closed position wherein the panels are vertically aligned with one another to form a closed door and a second open position wherein said panels are folded to an elevated position wherein the panels are disposed one on to of the other in a generally horizontal position with sat outer faces in a face-to-face relationship,

k. tensioning means mounted on each pair of connected 

1. A door assembly for a garage or the like comprising: a. an upper door panel adapted to be pivotably mounted at its upper edge for pivoting about a first generally horizontal axis, said upper panel having an inner face and an outer face, b. a lower door panel pivotably mounted to said upper panel to pivot about a second horizontal axis, said lower panel having an inner face and an outer face, c. tensioning means mounted on an inner face of said panels and connecting said upper and lower panels in a substantially vertical tensioning plane, d. said panels being movable from a closed position wherein said panels are vertically aligned to form a closed door in a plane which is disposed outwardly from and closely adjacent said tensioning plane, and a second open position wherein said doors are folded about said second horizontal axis and elevated to a position in which said outer faces of said panels are disposed in a face-to-face relationship, said second axis being disposed inwardly from said tensioning plAne, e. said tensioning means applying a closing moment to said panel about said second horizontal axis when said second axis is disposed outwardly from said tensioning plane and an opening moment when said second axis is disposed inwardly from said tensioning plane.
 2. A door assembly for a garage comprising: a. an upper door panel having an inner face, an outer face, an upper horizontal edge, a lower horizontal edge and a pair of oppositely disposed vertical side edges, b. a lower door panel having an inner face, an outer face, an upper horizontal edge, a lower horizontal edge and a pair of oppositely disposed vertical side edges, c. first hinge means for mounting said upper panel in a frame to permit pivoting about a first horizontal axis disposed adjacent said upper edge of said upper panel, d. second hinge means pivotably connecting said upper and lower panels to permit pivoting of said upper and lower panels relative to one another about a second horizontally extending axis disposed adjacent the lower edge of said upper panel and the upper edge of said lower panel, e. said upper and lower panels being pivotable about said first and second axes between a closed position wherein said panels are vertically aligned with one another to form a closed door and a second open position wherein said panels are folded to an elevated position wherein the panels are disposed one on top of the other in a generally horizontal position with said outer faces in a face-to-face relationship, f. said tensioner mounting means located below said first horizontal axis and secured to and extending rearwardly from the inner face of said upper panel, g. second tensioner mounting means secured to and extending rearwardly from the inner face of said lower panel, h. tensioning means mounted on said first tensioner mounting means and connected to said second tensioner mounting means and operable in a substantially vertical plane spaced rearwardly from and adjacent the plane of said doors when in said first closed position and connecting said first and second mounting means to apply a closing moment about said second horizontal axis when said second horizontal axis is disposed forwardly of the plane of said tensioning means and an opening moment when said second horizontal axis is disposed rearwardly of said tensioning plane.
 3. A garage door assembly comprising: a. a prefabricated frame having a pair of vertically extending support pillars and a horizontally extending support member connecting the upper ends of said supports to define a door opening, b. guide track means carried by at least one of said vertical members and extending longitudinally thereof, c. an upper door panel having an inner face, an outer face, an upper horizontal edge, a lower horizontal edge, and a pair of oppositely disposed vertical side edges, d. a lower door panel having an inner face, an outer face, an upper horizontal edge, a lower horizontal edge, and a pair of oppositely disposed vertical side edges, e. first hinge means pivotally mounting said upper panel on said horizontally extending frame member to pivot about a first horizontal axis disposed adjacent the upper edge of said upper panel, f. second hinge means pivotally connecting said upper and lower panels to permit pivoting of said upper and lower panels relative to one another about a second horizontally extending axis disposed adjacent the lower edge of said upper panel to the upper edge of said lower panel, g. guide track runner means secured to said lower panel and projecting into said guide track to reciprocate therein, h. said guide track runner means being disposed a substantial distance from said second horizontal axis to permit said guide track runner means to reciprocate within said guide track pivoting about said second horizontal axis, i. said upper and lower panels being pivotable about said first and second axes between a closed position wherein the panels are veRtically aligned with one another to form a closed door and a second open position wherein said panels are folded to an elevated position wherein the panels are disposed one on top of the other in a generally horizontal position with said outer faces in a face-to-face relationship, j. first tensioner mounting means located below said first horizontal axis and secured to and extending rearwardly from the inner face of said upper panel, k. second tensioner mounting means secured to and extending rearwardly from the inner face of said lower panel, l. tensioning means mounted on said first tensioner mounting means and connected to said second tensioner mounting means and operable in any substantially vertical plane spaced rearwardly from and adjacent the plane of said doors when in said first closed position and connecting said first and second tensioner mounting means to apply a closing moment throughout said second horizontal axis when said second horizontal axis is disposed forwardly of the plane of said tensioning means and an opening moment when said second horizontal axis is disposed rearwardly of said tensioning plane.
 4. An assembly as claimed in claim 1, including releasable locking means communicating between said upper door panel and said lower door panel to prevent pivoting about said second horizontal axis and thereby maintain said door in a closed position.
 5. A garage door assembly as claimed in claim 1 wherein said tensioning means comprises a pulley mounted for rotation on one of said door panels and a flexible cable connecting between said pulley and the other of said door panels, and drive means urging said pulley to rotate in a predetermined direction to apply tension to said cable means in all positions of said upper and lower door panel relative to one another.
 6. A garage door assembly as claimed in claim 1 wherein said tensioning means comprises a shaft rotatably carried by said upper door panel for rotation about a generally horizontal axis, coil spring means extending around the outer surface of the shaft and connected to it to urge said shaft to rotate in a predetermined direction, a pulley secured to one end of said shaft for rotation therewith, tension cable means connecting said pulley to said lower door panel, said spring means rotating said pulley to wind said tensioning cable onto said pulley when said door moves from said closed position to said open position.
 7. A garage door assembly as claimed in claim 6 wherein said pulley is conically shaped and formed with a helical groove receiving the tensioning cable, the tensioning cable being connected to the pulley in the area of the largest diameter.
 8. In a garage door assembly having a frame consisting of a pair of vertically extending support pillars and a horizontally extending support member connecting the upper ends of said support pillars, the improvement of, two door assemblies as claimed in claim 1 mounted in a side-by-side relationship.
 9. A garage door assembly as claimed in claim 8 including sealing means for sealing the oppositely disposed side edges of adjacent door panels.
 10. A garage door assembly as claimed in claim 8 including ground engaging lock means carried by the lower panels of each door.
 11. A garage door assembly as claimed in claim 8, including releasable locking means communicating between said upper door panels and said lower door panels to prevent pivoting about said second horizontal axis and thereby maintain said door in a closed position.
 12. A garage door assembly comprising: a. a prefabricated frame having a pair of vertically extending support pillars and a horizontally extending support member connecting the upper ends of said supports to define a door opening, b. guide track means carried by each of said vertical members and extending longitudinally thereof, c. a pair of door assemblies each comprising d. an upper door panel having an inner face, an outer face, an upper horizontal edge, a lower horizOntal edge, and a pair of oppositely disposed vertical side edges, e. a lower door panel having an inner face, an outer face, an upper horizontal edge, a lower horizontal edge, and a pair of oppositely disposed vertical side edges, f. first hinge means pivotally mounting each of said upper panels onto said horizontally extending frame member to pivot about a first horizontal axis disposed adjacent the upper edge of said upper panel, g. second hinge means pivotally connecting each pair of upper and lower panels to permit pivoting of each pair of connected upper and lower panels relative to one another about a second horizontally extending axis disposed adjacent the lower edge of said upper panel to the upper edge of said lower panel, h. guide track runner means secured to each lower panel and projecting into the guide track of the adjacent vertical support to reciprocate therein, i. said guide track runner means being disposed a substantial distance from said second horizontal axis to permit said guide track runner means to reciprocate within each of said guide tracks pivoting about said second horizontal axis, j. each connected pair of upper and lower panels being pivotable about said first and second axes between a closed position wherein the panels are vertically aligned with one another to form a closed door and a second open position wherein said panels are folded to an elevated position wherein the panels are disposed one on top of the other in a generally horizontal position with said outer faces in a face-to-face relationship, k. tensioning means mounted on each pair of connected panels below said first horizontal axis and operable in a substantially vertical plane spaced rearwardly from the plane of said doors when in said first closed position and connecting said upper and lower panels to apply a closing moment about said second horizontal axis when said second horizontal axis is disposed forwardly of the plane of said tensioning means and an opening moment when said second horizontal axis is disposed rearwardly of said tensioning plane. 